Hydraulic indexing mechanism for foundry turntables



HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURNTABLES 6 Sheets-Sheet 1 Filed May 11, 1959 llli IN V EN TOR. WWII-LIAM AHUNTEII Jan. 10, 1961 w. A. HUNTER HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURNTABLES Filed May 11, 1959 6 Sheets-Sheet 2 INVENTOR. WILLIAM UNTER 2M Jan. 10, 1961 w. A. HUNTER 2,967,440

HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURNTABLES Filed May 11, 1959 6 Sheets-Sheet 3 l\ 2 g Q ,9, q \O Q Q N QM g I Q I i & I 3;

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INVENTOR. WILLIAM A.HUN1'ER.

Jan. 10, 1961 w. A. HUNTER 2,967,440

HYDRAULIC mozxmc MECHANISM FOR FOUNDRY TURNTABLES Filed May 11, 1959 6 Sheets-Sheet 4 INVENTOR. WILUAM A. Human Mae Jan. 10, 1961 w. A. HUNTER HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURNTABLES Filed May 11, 1959 6 Sheets-Sheet 5 INVENTOR. 7e WILLIAM Amman ATTY.

Jan. 10, 1961. w. A. HUNTER 2,967,440

HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURNTABLES Filed May 11, 1959 6 Sheets-Sheet 6 CONTROL VALVE c 206 CONTROL VALVED CONTROL VALVE A DRIVE ROLLER 53 CONTROL VALVE E CONTROL VALVE B LOCKING ROLLER 6O wa er 2o luvaw'rok rates HYDRAULIC INDEXING MECHANISM FOR FOUNDRY TURN TABLES Filed May 11, 1959, Ser. No. 812,476 9 Claims. (Cl. 74-817) The improved turntable indexing mechanism comprising the present invention has been designed primarily for foundry use in connection with the periodic indexing of a turret-supported turntable through successive positions for flask and pattern transporting purposes between suc cessive operating stations. Accordingly, the invention has for exemplary purposes been illustrated herein as being associated with a turntable-supporting turret which is adapted to be periodically indexed or rotated through 90 increments of motion for the purpose of transporting a flask which has been filled and rammed at a sand slinging station to an inspection or strike-off station where the filled and rammed flask may be struck off and leveled and from thence to a pattern-removing station where the pattern is removed, the mold pushed away and the pattern returned to the turntable, and finally to a set-up station where a cope or drag flask is set on the pattern plate preparatory to return of the pattern to the sand' slinging station. By an arrangement of this character, a large number of foundry operations may be carried out in a relatively small floor space.

The invention is capable of other uses and the same may if desired with or without suitable modifications be employed for similar foundry operations involving vari ous modifications of the above briefly outlined steps, in the same or in a different sequence, or involving additional flask or pattern treating operations. For example, whereas in the embodiment of the invention illustrated herein, the turntable indexing mechanism of the present invention has been designed for use in effecting periodic movements of the turret turntable throughout an angle of 90, it is within the purview of the invention that the mechanism be designed to. impart rotational movement to the turret through other predetermined angles as for example 72 in a case where five operating stations are required, or 60 in a case where six operating stations are required. Furthermore, the invention is not necessarily limited to foundry use and the same may if desired with suitable modification if necessary, be employed for turntable or turret indexing operations associated with locomotive roundtables, missile launching platforms, artillery mounts in connection with ordnance and gunnery both mobile and stationary, observation platforms and for a wide variety of other uses too numerous to mention. Irrespective however of the particular use to which the present invention may be put, the essential features thereof are at all times preserved.

In general, the present invention is admirably suited for use and will find application in connection with the periodic indexing of relatively massive rotatable structures such as the flask-transporting turret and turntable structure illustrated herein. Due to the relatively great weight involved in such structures, high torque application is required at the commencement and termination of each indexing operation to overcome the correspondingly high coeflicient of static friction, as well as to overcome 2 both the inertia and momentum of the massive structure. According to the present invention, the indexing mechanism is so designed that the application of input torque to the turret during each indexing operation 18 a quantitative harmonic function commencing with the application or innmte torque, passing through an increment of minimum yet appreciable torque at the mid-cycle, and terminating in an infinite input torque. The mechanism is also designed so that forces resulting in acceleration are applied to the turret during the first half cycle of any given indexing operation while forces resulting in deceleration are applied to the turret during the second half cycle, the counter-torque thus applied being the result of the tendency for the relatively massive turret structure due to its kinetic energy and momentum to overrun the actual torque input element proper which during such second half-cycle resists such overrunnmg motion by the application of increasing increments of reverse or counter-torque to the turret. The extent of the application of such counter-torque to the turret during the second half-cycle of each indexing operation will of course be dependent upon both the speed of operation of the driving mechanism and the amount of frictional drag exerted upon the turret. N

The provision of a turntable indexing mechanismwhich as briefly outlined above will impart high initial torque to the turntable at the commencement of each indexingv operation and which also will impart a high degree of terminal counter-torque to the turntable at the conolu-. sion of each indexing operation constitutes one of the principal objects of the present invention.

It is another object of the invention in a turntable indexing mechanism of this character to provide a cyclicly operable mechanism including a traction drive element which is movable with the rotatable turret and which is periodically operable to engage a portion of the fixed turntable base and, by a stroke-performing operation, propel the turret throughout the full extent of each indexing operation, after which the element is automatically moved to a new position of engagement with the fixed turret base preparatory to the next succeeding propelling operation in the following machine cycle.

An additional object or the invention is to provide an hydraulic actuated cyclically operable turntable indexing mechanism of this general character in which the various sequential hydraulic functions which are effected during each indexing cycle are automatically initiated in their proper sequential relationship, each at the termination of a previous hydraulic function under the control of a movable element associated with such previous function as the element assumes its terminal position. By such an arrangement no function can be initiated untilthe previous function has been completed while, additionally, the use of timing devices such as control cams and the like is eliminated.

The provision of a turntable indexing mechanism which is relatively simple in its construction; one which is comprised of a minimum number of moving parts and which therefore is unlikely to get out of order; one which is rugged and durable and which therefore will withstand rough usage; one which is compact in its design so that it may be conveniently enclosed within the turret with which it is associated without necessitating turret enlargement or the use of turret extensions to accommodate its installation; one which is smooth and silent in its operation; one in which the various operative parts thereof are readily accessible for purposes of inspection, replacement of parts or repair; and one which otherwise is well adapted to perform the services required of it, are further desirable features which have been borne in mind in the production and development of the present invention.

In the accompanying six sheets of drawings forming a part of this specification one illustrative embodiment of the invention has been shown.

In these drawings:

Fig. 1 is a top plan view of a platform-supporting turret assembly to which a cvclicly operable, hydraulically actuated indexing mechanism constructed in accordance with the principles of the present invention has been operatively applied. In this view, certain parts have been broken away and other parts shown in section to more clearly reveal the nature of the invention;

Flg. 2 is a fragmentary top plan view, similar to Fig. 1 showing the indexing instrumentalities in the position they assume shortly after the commencement of an indexing cyc e;

Fig. 3 is a fragmentary top plan view similar to Fig. 1 showing the indexing mechanism in the position which it assumes after approximately the first quarter-cycle of its operation with the turret assuming its mid-position of displacement;

Fig. 4 is a fragmentary top plan view similar to Fig. 1 showing the indexing mechanism in approximately its mid-cycle position with the turret fully indexed;

Fig. 5 is a sectional view taken substantiallv along the line 5-5 of Fig. 1 with certain parts removed to simplify the disclosure;

Fig. 6 is an enlarged sectional view taken substantially along the line 6-6 of Fig. 5;

Fig. 7 is a sectional view taken substantially along the line 77 of Fig. 1;

Fig. 8 is a sectional view taken substantially along the line 8-8 of Fig. 6;

Fig. 9 is an enlarged sectional view partlv in elevation taken substantially along the line 9-9 of Fig. 6;

Fig. 10 is an enlarged detail plan view somewhat schematic in its re resentation of a portion of the indexing mechanism of the present invention and illustrating a power driving unit and certain associated structure emploved in connection with the invention;

Fig. 11 is a sectional view taken substantially along the line 11-11 of Fig. 10: and

Fig. 12 is a schema ic view of the hvdraulic control circuit by means of which the various hydraulic instrumentalities of the present invention are controlled.

BRIEF DESCRIPTION Referring now to Figs. 1, 5 and 6, the indexing mechanism of the present invention has for illustrative purposes. been shown as being operatively associated with a turret assembly designed for use as a base support for a foundry turntable. the details of which have not been shown herein but which will be understood to consist of lateral turret extensions which are secured to and project radially outwardlv from the periphery of the turret, suitable bolt holes 22 being provided in the rim region of the turret to accommodate the releasable fastening of the extensions in position. A fragmentary position of one such turret extension has been indicated at 23 in Fig. 4. When mounted on the turret, these extensions afford a generally planar operating surface and are adapted to have associated therewith the necessary instrumentalities for flask and pattern transporting operations between successive operating stations which in the illustrated form of the invention require that the turret and turntable supported thereby be periodically and successively indexed throughout an angle of 90. The various flask and pattern handling operations form no part of the present invention, it being deemed sufificient to state that the purpose of the 90 turret indexing operations is to move the various flask and pattern supporting instrumentalities as sociated with the turntable in the four respective sectors thereof into successive register with the four fixed operating stations located at regions spaced circumferentially apart around the periphery of the table so that repetitive molding operations may be carried out on a continuous basis.

Still referring to Figs. 1, 5 and 6, the rotatable turret proper is in the form of a casting providing an inverted cup-shaped shell or annulus 24 which is tractionally supported by means of a series of wheel assemblies 26 (see also Fig. 9) on a raised circular track or rail 28 associated with a fixed circular base member 30, likewise in the form of a casting. As best seen in Figs. 5 and 6, the base member 30 is formed with a central hub 32 from which there project radially outwardly a series of divergent guideways 34, the angles between adjacent guideways being 90.

The hub 32 serves to support a vertically extending shaft 36 which is surrounded by a central turret hub 38, suitable anti-friction bearing 40 being interposed between the hub 38 and shaft 36. A sleeve 42 surrounds the shaft 36 above the bearing 40 and, in combination with the shaft 36, affords an annular distribution chamber 44 for the hydraulic fluid which is employed for actuating the various control valves, motors and other hydraulic instrumentalities associated with the indexing mechanism of the present invention.

The indexing mechanism by means of which 90 increments of rotation may be applied to the turret assembly 24 to shift the same relative to the base member 30 is in the form of a modified Geneva mechanism including one or more turret driving arms 50, two such arms being shown in the present instance although a greater or lesser number of such driving arms may be employed if desired. The two arms 50 are identical in function and they are actuated simultaneously for turret-driving purposes. The arms 50 are pivotally mounted on the turret structure at diametrically spaced points for horizontal swinging movements about respective vertical axes and each arm carries at its distal end a vertically shiftable rollersupporting pin 52 carrying a roller 53 (see also Figs. 10 and 11) and which is movable between a lowered position relative to the arm wherein the roller 53 may selectively enter the various guideways 34, and an elevated position wherein the roller is out of register with these guideways.

Rotational movements of the arm 50 are effected under the control of a motor assembly hereinafter referred to as a hydromotor 54 by means of which the arm may be swung horizontally in either direction relative to the turret throughout an angle of approximately 270 between an extreme counterclockwise-limited position wherein it is shown in Fig. 1 and an extreme clockwise-limited position wherein it is shown in Fig. 4. Fig. 1 represents an initial or starting position of the turntable and turret assembly 24 prior to commencement of any given indexing cycle and in this position of the turntable the shiftable pin 52 assumes its lowermost position wherein the roller 53 is disposed within one of the guideways 34 at the extreme inner or proximate end of the guideway. At the commencement of the machine cycle wherein a single indexing operation is performed, the motor assembly 54 is supplied with hydraulic fluid and the arm 50 is caused to move in a clockwise direction from the position wherein it is shown in Fig. 1 throughout an angle of approximately 270. In Fig. 2 the arm 50 is shown as having moved from the position of Fig. 1 through a slight an le so that the roller 53 has been advanced radially outwardly in the slot or guideway 34 a short distance and the turret casting 24 has been moved in a counterclockwise direction through a very small angular displacement. Due to the character of the changing cosine function of the angle involved between the radial direction of extent of the guideway 34 and the direction of extent of the arm 59 at the commencement of the indexing cycle, extremely large increments of reaction thrust are applied against the side wall of the guideway 34 by the roller 53 and a powerful initial degree of torque is applied to the turret casting 24 tending to dislodge the same from its static condition'on the base member 30. As the roller 53 moves radially outwardly in the guideway 34, the cosine function constantly decreaess so that when the arm 50 has moved through an angle of 135 and is coaxial with the guideway as shown in Fig. 3, the turret casting 24 has moved through an angle of 45 with minimum torque application being exerted upon the turret casing. Throughout the next 45 of movement of the turret casting, the roller 53 moves radially inwardly in the slot or guideway 34 until such time as it reaches the limit of such inward movement as shown in Fig. 4.

Depending upon the extent of the coefficient of dynamic or running friction existing between the turntable casting 24 and the circular track 28, the kinetic energy of the turret and structure supported thereby may create a tendency for an overrunning condition to exist. However, due to the fact that during inward movement of the roller 53 in the guideway 34, the cosine function is a constantly decreasing one, a steadily increasing degree of counter-torque is applied to the turret casting by the reverse reaction thrust offered to the roller 53, and consequently the arm 50 by the opposite side of the slot or guideway 34. The tendency for the turret to thus overrun the indexing operation is thus effectively damped and the turret is brought to a standstill at a position 90 angularly removed from its initial position when the arm 50 has completed its clockwise angular sweep of 270". At this point the indexing cycle may be regarded as having progressed to approximately its mid-point.

As soon as the turret has terminated its movement and the arm 50 assumes the position wherein it is shown in Fig. 4, the roller supporting pin 52 and roller 53 carried thereby become elevated, thus withdrawing the roller from the radial guide channel or slot in which it has travelled during the first half of the indexing cycle and freeing the arm for restorational movement to its initial position of angularity relative to the turret. Accordingly, hydraulic fluid is again supplied to the motor assembly 54 which is caused to move in a counterclockwise direction throughout an angle of 270 whereupon the pin 52 and roller 53 move into vertical register with the inner or proximate end of the next adjacent guideway 34 forwardly in the direction of rotation of the turret. At this point in the cycle, the pin 52 and roller 53 are lowered so that the roller enters the proximate end of the guideway at a point near the end of the cycle.

Actual movement of the turret under the control of the swinging arm 50 is preceded by an initial turret-unlocking operation wherein a locking roller 60 (Figs. 1 and 8) which is movably mounted on the turret casting 24 is caused to become elevated and is thus withdrawn from its seat provided in one of a series of four blocks 62 adjustably mounted on the base member or casting 30. The blocks are disposed in the vicinity of the respective operating stations around the turntable and are capable of limited circumferential adjustment relative to the turret so that the various indexed positions of the turret may be accurately determined for proper registry of the mold, the pattern and other mold instrumentalities with the handling mechanisms at these various stations. Restorational movement of the arm 50 to its initial or original position relative to the turret near the end of the cycle is followed by a lowering of the locking roller into seating engagement with the next adjacent block 62 forwardly in the direction of rotation of the turret.

The various operations outlined above take place during each indexing cycle under the control of certain hydraulically operable valve mechanisms and cam actuating devices therefor the nature and function of which will become clear subsequently when the combined hydraulic circuit and timing chart of Fig. 12 is explained. It is to be noted however at this point that the various valve controlled operations take place sequentially and that each operation is effected under the control of the terminal "6 movement of a cam actuator associated with the next preceding operation so that each indexing cycle embodies a chain reaction, so to speak, which is carried to completion near the end of the cycle.

THE TURRET ASSEMBLY (The base casting) Referring now to Figs. 5, 6 and 7, the base casting 30 is generally of circular design and is in the form of a flat disk-like plate 70 having a raised rim portion 71, the crown portion of which affords the previously mentioned circular platform-supporting rail 28. Each of the four guideways 34 exists by virtue of a pair of spaced parallel generally radially extending upstanding ribs 72 which are reinforced by gusset webs 74 and which have secured'to their opposed inside faces a pair of replaceable wear plates 76, the spaces between the wear plates constituting the guideways proper. I

The central hub 32 is of generally frusto-conical design and is formed with a central opening 78 therethrough designed for reception therein of a center'post 80 associated with an hydraulic swivel manifold assembly 82 by means of which hydraulic fluid is supplied to the various control devices associated with the indexing mechanism and the nature and function of which will be made clear presently. The base casting 30 may be fixedly secured to an underlying base plate (not shown) suitable bolt holes or openings 84 being formed in the circular plate 70 to receive therethrough bolts or other fastening devices (not shown).

. (The turret casting) The turret casting 24 is of inverted cup-shape configuration and includes an outer side wall of stepped design providing an upper rim portion 92, a flat annular upper step portion 94 in which the various turntable bolting holes 22 are formed, an inclined portion 96, a lower (The traction support for the turret casting) As best seen in Figs.'5, 6 and 9, the turret casting 24 is tractionally supported on the rail 28 by means of a series of twelve of the wheel assemblies 26, the assemblies being equally and circumferentially spaced about the interior of the casting, and being mounted on the depending apron portion 1% thereof. Each wheel assembly, as best seen in Fig. 9, includes a wheel-supporting eccentric shaft 110 which is flanged as at 112 at one end with the axes of the shaft and flanges being slightly offset from each other. The flange 112 is circular and seats within a circular recess 114 formed on the inside face of the turret apron 100. The flange 112 is maintained seated Within the recess 114 by means of a retaining sleeve or nut 116 fastened to the apron by screws 118. A dual bearing assembly 129 is disposed on the shaft and is retained thereon by a bearing lock nut 122. The wheel proper is in the form of a ring 124 which is carried by the outer race of the bearing assembly 120. It is to be noted that the rail 28 is inclined in a trans verse direction radially outwardly of the base casting 30 while the outer surface of the wheel 124 is of frustoconical configuration of relatively small slant angle conforming to the angle of inclination of the rail 28.

THE TURRET LOCKING INSTRUMENTALITIES In the illustrated embodiment of the present invention, means are provided for releasably locking the turret casting 24 in each of the four positions of circumferential angularity which it is capable of assuming, the angle between adjacent positions being 90. In the illustrated form of the invention the releasable locking mechanism includes the previously mentioned locking roller 60 which is movably on the turret casting and which is designed for cooperation with the four seat-providing blocks 62. The roller 60 is rotatably mounted as at 130 adjacent the distal end of an arm 132 which has its proximate end pivoted as at 134 on a lug 136 formed on the inside face of the apron portion 100 of the turret casting. The outer end of the arm 132 is connected as at 134 to the plunger 136 associated with a cylinder and piston assembly 1.325 suitably mounted on an overlying portion of the turret casting 24.

The locking wheel 60 is adapted to seat within a recess or depression 140 formed in the block 62, the block being circumferentially adjustable on the base plate 70 between a pair of spaced lugs 142 integrally formed on the plate, suitable threaded adjusting screw assemblies 144 being provided for effecting such adjustment. it will be seen therefore that the terminal position of the turret at any one of the various positions of which it is capable of assuming may within small limits be adjusted for the purpose of bringing any mold and flask handling mechanism or instrumentalities which may be associated with the turret at the various operating stations into accurate register with the turret-supported devices.

THE TURRET INDEXING MECHANISM (T he turret driving arm assembly) The details of the turret driving arm assembly appear in Figs. 1 to 4 inclusive but they are best illustrated in Figs. and 11 wherein the turret driving arm proper 50 is shown as having its proximate end fixedly secured or clamped as at 150 to the rotary output shaft 152 of the previously mentioned reversible hydraulically operated motor assembly 54. As shown in Figs. 1 to 4 inclusive, the two motor assemblies 54 for supporting the respective turret driving arms 50 are bolted or otherwise secured as at 153 to a pair of motor mounting plates 154 which in turn are secured as at 155 to certain of the web members 104 at diametrically opposed regions of the turret. The hydraulic motors 54 are of conventional design and no claim is made herein to any novelty associated with the same except insofar as it is associated in the hydraulic circuit of the turret indexing mechanism.

Briefly, as shown in the circuit diagram of Fig. 12 the motor assembly 54 includes a generally cylindrical casing 156 within which there is pivoted for swinging movement about the central axis of the casing a vane 158, the vane being movable within the casing throughout an angle of 270 from the initial position wherein it is shown in full lines in Fig. 12 and wherein it abuts against a stop 159 to the terminal position shown in dotted lines and wherein it abuts against a stop 161. The movable vane 158 con stitutes in effect an extension of a fixed radial wall 163 so that when hydraulic fluid under pressure is admitted through the port 165, the vane 158 will be progressively forced toward and against the stop 161. When hydraulic fluid under pressure is admitted through the port 167, the vane 158 will be forced toward and against the stop 159. The vane 158 is mounted on and carried by the shaft 152. The arm 50 is thus movable bodily with the vane 158 so that it is capable of swinging movements throughout an angle of 270 between the position which it assumes at the commencement of each machine cycle as illustrated in Figs. 1 and 10 and the position which it assumes at approximately the mid-point or 180 in the indexing cycle after the turret has been indexed through an angle of 90 as shown in Fig. 4. As previously set forth, in the p sition of the turret shown in Fig. l, the arm 50 overlies the extreme inner end region of one of the guideways 34. In the position of the turret shown in Fig. 4, the distal end of the arm overlies the inner end of the same guideway but the end of the arm has completely traversed the guideway 34 and returned to its innermost position while the turret has been advanced to an angle of 90.

The outer or distal end of the arm 50 is provided with an enlarged boss 160 within which boss the previously mentioned shift pin 52 is vertically slidable (Figs. 7, 10 and 11). The upper end of the shift pin 52 projects upwardly above the boss 160 and is formed with a slot 162 in one side thereof designed for selective reception therein of a pair of lifting fingers 164 and 166 respectively, carried on a pivoted yoke assembly 168, the nature and function of which will be made clear presently. In the position shown in Figs. 1 and 10 at the commencement of the indexing cycle, the slot 162 is engageable with the lift ing finger 164 while, in the position shown in Fig. 4 the slot 162 is engageable with the lifting finger 166.

From the above description it will be seen that when the shift pin 52 is in its lowermost position as shown in Fig. 11 with the roller 53 carried thereby disposed within one of the guideways 34, actuation of the hydraulic motor 54 in a direction to cause clockwise rotation of the arm 50 as viewed in Fig. 1 will effect counterclockwise rotation of the turret casting 24, providing of course that the turret locking mechanism previously described and including the block and roller counterparts 60, 62, are in their positions of turret release. At such time as the shift pin 52 is in its elevated position and the roller 53 carried thereby is out of register with the guideway 34, actuation of the motor 54 in a direction to cause counterclockwise rotation of the arm 50 as viewed in Fig. 4, will effect no turret movements, but will merely restore the arm to its initial position relative to the turret casting wherein the roller 53 overlies or is in vertical register with the inner end of the next adjacent guideway 34 preparatory to being lowered into such guideway for a succeeding indexing cycle. The impelling operation of the arm 50 may be compared roughly to the propelling action of an oar associated with a row boat in that the oar frictionally or tractionally engages the supporting medium and, operating in the manner of a first class lever, forces the boat forwardly, after which the distal end of the air is withdrawn from the water and caused to seek a new purchase thereon at a region advanced forwardly of the fulcrum point of the oar. If there is a delay in withdrawing the oar from the water a re tarding action opposing the kinetic energy of the boat will be effected as in the present instance where overrunning of the turret is prevented due to the reverse action of the roller 53 as it moves inwardly along the guideway 34 as previously described.

(The driving roller lifting mechanism) Referring now to Figs. 7 and 10, the means for moving the shift pin 62 between its elevated and lowered positions at the proper points in the indexing cycle includes the previously mentioned yoke assembly 168. The yoke assembly 163 comprises a pair of yoke arms 170 which are connected together by a transverse yoke bar 172. The proximate ends of the yoke arms 170 are pivoted as at 174 in respective brackets 176 secured to the turret frame structure and the lift pins 164 and 166 are adjustably mounted as at 177 to the distal ends of the arms 170 respectively. A pair of attachment ears 178 (Fig. 11) are formed on the yoke bar 172 and are operatively connected as at 180 to a plunger 182 associated with a piston and cylinder assembly 184 pivotally suspended as at 186 between a pair of ears 183 provided on the motor mounting plate 163. The operation of the piston and cylinder assembly 184 at the proper time in the indexing cycle will be apparent when the combined hydraulic circuit diagram and timing chart of Fig. 12 is discussed. It is deemed sufficient for the present to state that upon elevation of the plunger 182 the entire yolk assembly 168 will be swung upwardly to elevate the pins 164 and 166. Conversely, upon lowering of the plunger 182, the pins 164 and 166 will become lowered. At the commencement of an indexing cycle the plunger 182 will be maintained in its lowered position and the slot 262 provided in the shift pin -52-will receive the pin 164i therein as shown in Fig. by virtue of the arm 50 having been moved during a preceding indexing cycle'into register with the elevated pin 164 and by virtue'of this pin having descended to its lowermost position to seat the roller 53 in the guideway 34 at the inner end of the latter. Early in the indexing cycle the guide pin will move away from the pin 164 as the arm r54! moves in a clockwise direction as viewed in Fig. 10. The slot 162 by its revolution about the axis of the motor 54 will face generally in an opposite direction at the time the arm has moved through an angle of 273 so that the slot will move into register with and engage the pin 166 which also is in its lowered position at substantially the midpoint in the indexing cycle as the turret approaches its terminal indexed position. As will be described presently, the plunger 3182' becomes elevated at approximately the mid-point in the indexing cycle and causes the roller 53 to be raised from the guideway 34. Thereafter the hydraulic motor 54 is actuated to swing the arm 50 in a counterclockwise direction as viewed in Fig. 10 so that the pin 52 sweeps in a reverse direction through an angle of 270 and approaches the lifting finger 164 which is then elevated so that it may again receive the slot 162 preparatory to descent of the plunger 182 and consequent lowering of the roller 53 into the next adjacent guideway 34.

As best seen in Fig. 11 the shift pin 52 is adapted to be held in its elevated and lowered positions by means of a detent assembly 189 carried in the distal end of the arm and which cooperates with a pair of detent sockets 1% formed at the opposite ends of a vertical slot 19 3 provided in the shift pin 52. The pin is thus held against turning movement in the arm while at the same time being capable of vertical shifting movement between its elevated and lowered positions.

(The control valve instrumentalities) As previously stated, the indexing mechanism of the present invention is cyclicly operable under the control of a series of valve instrumentalities only certain of which appear in Figs. 1 to 4 inclusive, 10 and 11, but all of which appear in Fig. 12. These valve instrumentalities include a series of five main control valves .Which for convenience of description have been designated by the capital letters A, B, C, D and E respectively, together With certain auxiliary valve and other hydraulic instrumentalities which have been given numeral designations as will be encountered subsequently. Control valves A and B supply hydraulic fluid through lines 2% and 2% respectively to the opposite ends of the previously mentioned piston and cylinder assembly 184 by means of which the shift pin 52 and driving roller 53 carried thereby are elevated to their inoperative position and lowered to their operative position. Control valve B is also con nected through a line 2%?! to the upper end of the cylinder and piston assembly 138 by means of which the locking roller 6!? is lowered into engagement with the block 6% for turret locking purposes. Control valve C supplies fluid through a line 204 to one side of a directional valve 206, for application of the fluid through a line 208 to the hydraulic motor 54 for driving the same in a counterclockwise direction as viewed in Fig. 12 during the second half of the indexing cycle to restore the elevated shift pin 52 to its engagement with the lifting finger 164. Control valve D supplies fluid through a line 21 8 to the directional valve 2% for subsequent application through a line 212 leading to the hydraulic motor 54 for driving the latter in a clockwise direction to carry the lowered shift pin and roller outwardly in the guideway 34 during the first half of the indexing cycle to advance the turret throughout an angle of 90 and bring the shift pin 52 into register and engagement with the lifting finger 166. Ce t a a e E i a manua y cps a le valve a s a manual actuation thereof hydraulic fluid is supplied to V ,the piston and cylinder assembly 138 through a line 214 to raise the plunger 136 and elevate the locking roller 60 from its seat in the block 62.

The valves A, B, C, and D have associated therewith respective actuating fingers a, b, c and d respectively, each of which is adapted to be engaged by a movable element associated with a previous function in the indexing cycle so that the various valves will be actuated in sequential relationship. The valve E has associated therewith a manually operable actuating finger e operable under the control of a handle 220 for initiating any given machine cycle.

(The valve actuating cam control mechanism) Referring now to Figs. 10 and 11, the control valve' A is suitably mounted on a bracket 222 suspended from a portion of the turret framework 24 and the actuating finger a associated therewith is positioned in the path of movement of a trip lever assembly 224 in the form of a bell crank lever pivoted as :at 226 to the bracket 222 and having a relatively short arm 228 engageable with the finger a and a relatively long arm 230 carrying a cam piece 232 which, under the influence of a biasing spring 234, is normally positioned in the path of movement of the end of the arm 50 as the latter moves toward its terminal position at the end of an indexing cycle. A trip lever assembly 2% and which therefore need not be described in detail is pivotally mounted on a bracket 242 likewise suspended from a portion of the turret framework and is in position in the path of movement of the distal end of the arm 5d as the latter approaches mid-cycle position wherein the turret casting 24 moves toward its completely indexed position. Engagement of the cam piece 232 of the assembly 24-0 will cause depression of the actuating finger b of the control valve B.

The actuating finger 0 associated with the valve C is adapted to be engaged by a suitable abutment such as the abutment 25% shown in Fig. 12 which may be carried on a movable element of the actuating mechanism for the shift pin 52. The actuating finger d or" the valve D may be positioned in the path of movement of a similar abutment 252 provided on the movable element associated with the mechanism for actuating the locking roller an.

THE INDEXING OPERATIGN It is believed that from the foregoing description the 7 operation and many advantages of the improved indexing mechanism of the present invention will be fully understood and appreciated without further detailed description. However, a. brief resume of the machine operation with reference to Fig. 12 may lead me better understanding of the invention. Upon actuation of the control handle 220 hydraulic fluid will be supplied to the line 2114 to the underneath side of the piston and cylinder assembly 138 so that at the commencement of the indexing cycle the locking roller 60 will be raised from its seat on the block 62 thus releasing the turret for forward movement in a circumferential direction. At approximately 10 in the indexing cycle the abutment 252 engages the actuating finger d for the control valve D, whereupon fluid is admitted through the line 210 to the directional valve and from thence through the line 212 to the hydraulic motor 54 which is operated in a clockwise direction, thus swinging the driving arm 50 in a clockwise direction as viewed in Figs. 1 to 4 inclusive and causing the roller 53 carried thereby, which at the commencement of the cycle is in its lowered position, to ride outwardly in the gnideway 34 and pass through the position shown in Figs. 2 and 3 to the position wherein it is shown in Fig. 4. During this time, the turret is advanced through an angle of and'it reaches its terminal position at approximately in the indexing cycle at which time the distal end of the arm 50 engages the bell crank trip lever 240 (Fig. which in turn engages the actuating finger b of the control valve B. Actuation of the control valve B causes fluid to pass through the line 205 to the piston and cylinder assembly 138 whereupon the plunger 136 is lowered and the locking roller 60 again becomes seated in the block 62, thus locking the turret casting 24 against further rotation. At the time the control valve B is initially actuated fluid also passes through the line 2&2 to the lower end of the piston and cylinder assembly 134, thus driving the plunger 182 upwardly and causing the actuating finger 168 to elevate the shift pin 52 and roller 53 carried thereby. Movement of the roller 53 out of the guideway 34 serves to free the arm 50 from the confining influence of the guideway and thereafter, upon engagement of the abutment 256 with the actuating finger c for the control valve C, fluid is admitted through the line 204 to the direction valve 206 and from thence through the line 208 to the hydraulic motor 54 which is driven in a counterclockwise direction to restore the arm 50 to its initial position. As the arm arrives at its initial position, the distal end thereof engages a bell crank trip lever assembly 224 which in turn engages the actuating finger a of the control valve A. Actuation of the control valve A causes fluid to pass through the line 200 to the upper end of the piston and cylinder assembly 184, whereupon the plunger 182 is lowered and the operating finger 168 causes the shift pin 52 and roller 53 carried thereby to be lowered into the next succeeding guideway 34 thus terminating the indexing cycle.

The invention is not to be limtied to the exact arrangement of parts shown in the accompanying drawings or described in this specification since various changes in the details of construction may be resorted to without departing from the spirit of the invention. For example, while the indexing mechanism of the present invention has been illustrated and described as being hydraulically actuated, it is within the scope of the present invention to employ pneumatic or electrical means for both the actual application of torque to the turret to effect its turning movements, as well as to effect the sequential operation of the various control devices associated with the indexing mechanism. Furthermore, although the turret structure has been illustrated as being unidirectional in its rotary motion, it is contemplated that the various control devices may be sequentially operated in such a manner that the turret may be rotated in either direction at will. It is also within the scope of the invention to form the guideways 34 on the turret casting 24 and cause the drive cams 50 to be appropriately pivoted on the base casting 30. Only insofar as the invention has particularly been pointed outin the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

l. The combination with a fixed turret base and a turret mounted on said base for rotation about a central vertical axis, or indexing means for periodically rotating said turret to impart thereto successive angular displacements of equal magnitude, said indexing means comprising a pair of guide-forming elements on said base and providing a pair of generally radially extending diverging guideways, a drive arm pivoted to said turret at a point removed from said central axis and within the overall circumferential confines of said guideways for swinging movements in opposite directions about a horizontal axis and in a fixed horizontal plane between one extreme position wherein the distal end of said arm is in vertical register with the inner end of one of said guideways and another extreme position wherein the distal end of the arm is in vertical register with the inner end of the other guideway, a vertically shiftable element on the distal end 'of said arm and selectively engageable with said guideways when said distal end is in register therewith, means for swinging said guide arm in opposite directions, and means operable when said guide arm is in either extreme position for shifting said vertically shiftable element into and out of engagement with the guideway with which it is in register in such extreme position.

2. The combination set forth in claim 1 wherein the distal end of said drive arm is formed with a vertical bore, and wherein said vertically shiftable element is in the form of a shift pin, said shift pin being slidable vertically in said bore, a drive roller carried at the lower end of said shift pin and movable bodily with the latter, said shift pin being slidable between an elevated position wherein said roller is above the level of said guideways and a lowered position wherein the roller is capable of being confined between the channel-defining members of either pair of guide-forming elements.

3. The combination with a base member and a turret member mounted thereon for rotation about a central vertical axis, of indexing means for periodically rotating said turret member. to impart successive angular displacements of equal magnitude and in the same direction, said indexing means comprising a plurality of guide-forming elements on one of said members and providing a series of radially diverging guideways, the angle between each adjacent pair of guideways being equal, a drive arm piv' oted to the other member at a point removed from said central axis for limited swinging movements in opposite directions about a horizontal axis and in a fixed horizontal plane between two extreme positions, the point of pivotal connection between the arm and said other member and the extent of horizontal swinging movement of which the arm is capable being such that the distal end of the arm will move into vertical register with the inner end regions of adjacent guideways at the termination of the swinging stroke of the arm in opposite directions respectively, means for swinging said guide arm in opposite directions. a vertically shiftable element movably mounted on the distal end of said arm and selectively engageable with said guideways when the distal end of the arm is in register therewith, means operable when the guide arm is in one extreme position for shifting said vertically shiftable element relatively to the guide arm and into engagement with the guideway with which it is in vertical register, and means operable when the guide arm is in its other extreme position for shifting said vertically shiftable element relatively to the guide arm and out of engagement with the guideway to free said arm for swinging movement independent of said one member.

4. The combination set forth in claim 3 wherein said guide-forming elements are in the form of spaced channeldefining members and wherein said vertically shiftable element comprises a shift pin slidable in the arm between a position of horizontal registry with said guideways and a position out of such horizontal registry.

5. The combination set forth in claim 3 including, additionally, cooperating detent means on said vertically shiftable element and guide arm for maintaining said element in its shifted position during the independent swinging movement of said guide arm.

6. The combination set forth in claim 4 wherein said shift pin includes a drive roller movable with the shift pin bodily into and out of register with the guideways.

7. The combination with a base member and a turret member mounted thereon for rotation about a central vertical axis, of indexing means for periodically rotating said turret member to impart successive angular displacements thereto of equal magnitude and in the same direction, said indexing means comprising a plurality of guideforming elements on one of said members and providing a series of radially diverging guideways, the angle between each adjacent pair of guideways being equal, a drive arm pivoted to the other member at a point removed from said central axis for limited swinging movements in opposite directions about a horizontal axis between two extreme positions, the point of pivotal connection between the arm and said other member and the extent of horizontal swinging movement of which the arm is capable being such that the distal end of the arm will move into vertical register with the proximate end regions of adjacent guideways at the termination of the swinging stroke of the arm in opposite directions respectively, a reversible motor operatively connected to said drive arm for moving the same in opposite directions, a first control device operable upon actuation thereof to effect operation of the motor in one direction, a second control device operable upon actuation thereof to eifect operation of the motor in the other direction, a drive element designed for sliding cooperation with said guideways and mounted for vertical shifting movement at the distal end of said drive arm, a second reversible motor operatively connected to said drive element for shifting the same vertically in opposite directions, a third control device operable upon actuation thereof to effect operation of the second motor in one direction, a fourth control device operable upon actuation thereof to effect operation of the second motor in the other direction, and automatic means for actuating said first, third, second and fourth control devices sequentially in the order named.

8. The combination with a base member and a turret member mounted thereon for rotation about a central vertical axis, of indexing means for periodically rotating said turret member to impart successive angular displacements thereto of equal magnitude and in the same direction, said indexing means comprising a plurality of guideforming elements on one of said members and providing a series of radially diverging guideways, the angle between each adjacent pair of guideways being equal, a drive arm pivoted to the other member at a point removed from said central axis for limited swinging movements in opposite directions about a horizontal axis between two extreme positions, the point of pivotal connection between the arm and said other member and the extent of horizontal swinging movement of which the arm is capable being such that the distal end of the arm will move into vertical alignment with the proximate end regions of adjacent guideways at the termination of the swinging stroke of the arm in opposite directions respectively, a reversible hydraulic motor operatively connected to said drive arm for moving the same in opposite directions, a first control valve operable upon actuation thereof to admit fluid to said motor to operate the same in one direction, a second control valve operable upon actuation thereof to admit fluid to said motor to operate the same in the other direction, a drive element designed for sliding codirections into and out of register with said guideways,

a third control valve operable upon actuation thereof to admit fluid to said piston and cylinder assembly to shift the drive element out of register with a guideway with which the distal end of the arm is in alignment, a fourth control valve operable upon actuation thereof to admit fluid to said piston and cylinder assembly to shift the drive element into register with a guideway with which the distal end of the arm is in alignment, and automatic means for actuating said first, third, second and fourth control valve sequentially in the order named.

9. The combination with a base and a turret mounted thereon for rotation about a central vertical axis, of indexing means for periodically rotating said turret to impart successive angular displacements thereto of equal magnitude and in the same direction, said indexing means comprising a plurality of seat-forming members equally and circumferentially spaced about the peripheral regions of the base, a vertically movable locking element on said turret and selectively engageable with said seat-forming members for securing said turret in the various indexed positions of which it is capable of assuming, a first piston and cylinder assembly operatively connected to said locking element for raising and lowering the same out of and into operative engagement with said seat-forming members, means providing a series of radially diverging guideways on said base, the angle between adjacent guideways being equal, a drive arm pivoted to said turret at a point removed from said central axis, for limited swinging movements in opposite directions about a horizontal axis between two extreme positions, the point of pivotal connection between the arm and turret and the extent of swinging movement of which the arm is capable being such that the distal end of the arm will move into vertical register with the proximate end regions of adjacent guideways at the termination of the swinging stroke of the arm in opposite directions respectively, a reversible hydraulic motor operatively connected to the drive arm for moving the same in opposite directions, respectively, a drive element designed for sliding cooperation with said guideways and mounted for vertical shifting movement at the distal end of said drive arm, a second piston and cylinder assembly operatively connected to said drive element for shifting the same vertically in opposite directions into and out of register with said guideways, a first control valve operable upon actuation thereof to admit fluid to the first piston and cylinder assembly to raise said locking element, a second control valve operable upon actuation thereof to admit fluid to said hydraulic motor to operate the same in one direction, a third control valve operable upon actuation thereof to admit fluid to said second piston and cylinder assembly to shift the drive 'element out of register with a guideway with which the distal end of the drive arm is in vertical register, said third control valve also being operable upon actuation thereof to admit fluid to said first piston and cylinder assembly to lower said locking element, a fourth control valve operable upon actuation thereof to admit fluid to said hydraulic motor to operate the same in the other direction, a fifth control valve operable upon actuation thereof to admit fluid to said second piston and cylinder assembly to shift the drive element into register with a guideway with which the distal end of the drive arm is in vertical register, and automatic means for actuating said first, second, third, fourth and fifth control valves sequentially in the order named.

References Cited in the file of this patent UNITED STATES PATENTS 241,933 Collyer May 24, 1881 572,904 Micou Dec. 8, 1896 646,287 Hundhausen Mar. 27, 1900 1,405,058 Moore Jan. 31, 1922 2,531,198 Bruet et al Nov. 21, 1950 2,557,837 Opel June 19, 1951 2,757,559 Carpenter Aug. 7, 1956 2,801,553 Reynolds Aug. 6, 1957 2,898,780 Carlson et al Aug. 11, 1959 FOREIGN PATENTS 921,609 Germany Dec. 23, 1954 

